Power set: Difference between revisions

Content added Content deleted

Inline

@@ Line 1,078: / Line 1,078: @@
 =={{header|Prolog}}==
 <lang prolog>
-%powerset(Lst, PLst).
+powerset(Set,PowerSet) :-
+    findall(SubSet,subset(Set,SubSet),PowerSet).
-addhead(Hd,Lst,Res):-
-    Res = [Hd |Lst].
-head([H|_],H).
+subset([],[]).
+subset([_|Tail],Set) :- subset(Tail,Set).
-tail([_|T],T).
+subset([Head|Tail],[Head|Set]) :- subset(Tail,Set).
-powerset([], [[]]).
-powerset(Lst, PLst):-
-    head(Lst,Hd),
-    tail(Lst,Tl),
-    powerset(Tl,Rest),
-    maplist(addhead(Hd), Rest, Ans),
-    append(Rest, Ans, PLst).
-e.g
-powerset([1,2,3,4], R), write_term(R, [max_depth(100)]).
-[[],
- [4], [3], [3, 4], [2], [2, 4], [2, 3], [2, 3, 4],
- [1], [1, 4], [1, 3], [1, 3, 4], [1, 2], [1, 2, 4],
- [1, 2, 3], [1, 2, 3, 4]]
+?- powerset([1,2,3,4],X).
+X = [[], [4], [3], [3, 4], [2], [2, 4], [2, 3], [2, 3, 4], [1], [1, 4], [1, 3], [1, 3, 4], [1, 2], [1, 2, 4], [1, 2, 3], [1, 2, 3, 4]].
 </lang>
 =={{header|PureBasic}}==
 This code is for console mode.